Calculation prodigies, i.e., individuals characterized by exceptional arithmetic skills, have been tested since the dawn of experimental psychology. However, little is known about whether calculation prodigies differ from other individuals in very basic number processing. To investigate this, single-digit Parity Judgment and Magnitude Classification tasks were used and standard effects like distance, size, SNARC, MARC and odd effects were investigated and compared to control groups. We tested GM, a prodigy holding world records in mental calculation, e.g., calculating the 13th root of a 100-digit number, acting German champion in calculation. With bootstrapping, we tested whether GM revealed hallmark effects of basic number processing and estimated corresponding CI. We compared his performance to mathematicians, engineers, professionals in social sciences and humanities, and a sample from the general population. GM’s performance in these tasks was generally similar to control groups. We found distance and size effects, which can be seen as evidence for representing numbers in an analogue way. Presence of the SNARC effect in the magnitude task, but not in the parity task suggests that GM does associate magnitudes with space when magnitudes are needed for the task. Presence of MARC and odd effects indicate similar parity representation and their associations with space as in control samples. In conclusion, hallmark effects in basic number processing do not seem to be different in a prodigy. Nevertheless, there might be some intraindividual differences in the prodigy’s profile, whose difference to the control group may be masked by substantial interindividual variability in unselected populations.